Heterocyclic Organic Compounds As Electron Donors for Polyolefin Catalysts

ABSTRACT

Heterocyclic organic compounds are used as electron donors in conjunction with solid Ziegler-Natta type catalyst in processes in which polyolefins such as polypropylene are produced. The electron donors may be used in the preparation of solid catalyst system, thus serving as “internal electron donors”, or they may be employed during or prior to polymerization with the co-catalyst as “external electron donors”.

BACKGROUND

1. Field of the Invention

This invention relates to heterocyclic organic compounds that may beemployed as an electron donor for polymerization catalyst systems, topolymerization catalyst systems employing the heterocyclic organiccompounds as an electron donor, to methods of making such polymerizationcatalyst systems, and to polymerization processes to producepolyolefins, particularly polypropylene, which does not contain aphthalate derivative.

2. Description of the Related Art

Ziegler-Natta catalyst systems for polyolefin polymerization are wellknown in the art. Commonly, these systems are composed of a solidZiegler-Natta catalyst component and a co-catalyst component, usually anorganoaluminum compound. To increase the activity and sterospecificityof the catalyst system for the polymerization of α-olefins, electrondonating compounds have been widely used (1) as an internal electrondonor in the solid Ziegler-Natta catalyst component and/or (2) as anexternal electron donor to be used in conjunction with the solidZiegler-Natta catalyst component and the co-catalyst component.

In the utilization of Ziegler-Natta type catalysts for polymerizationsinvolving propylene or other olefins for which isotacticity is apossibility, it may be desirable to utilize an external electron donor,which may or may not be in addition to the use of an internal electrondonor. Acceptable external electron donors include organic compoundscontaining O, Si, N, S, and/or P. Such compounds include organic acids,organic acid esters, organic acid anhydrides, ethers, ketones, alcohols,aldehydes, silanes, amides, amines, amine oxides, thiols, variousphosphorus acid esters and amides, etc. Preferred external electrondonors are organosilicon compounds containing Si—O—C and/or Si—N—Cbonds, having silicon as the central atom. Such compounds are describedin U.S. Pat. Nos. 4,472,524; 4,473,660; 4,560,671; 4,581,342; 4,657,882;5,106,807; 5,407,883; 5,684,173; 6,228,961; 6,362,124; 6,552,136;6,689,849; 7,009,015; 7,244,794; 7,619,049; and 7,790,819, which areincorporated by reference herein.

Common internal electron donor compounds, incorporated in the solidZiegler-Natta catalyst component during preparation of such component,known in the prior art, include ethers, ketones, amines, alcohols,phenols, phosphines, and silanes. It is well known in the art thatpolymerization activity, as well as stereoregularity, molecular weightand molecular weight distribution of the resulting polymer, depend onthe molecular structure of the internal electron donor employed.Therefore, in order to improve the polymerization process and theproperties of the resulting polymer, there has been an effort and desireto develop various internal electron donors. Examples of such internalelectron donor compounds and their use as a component of the catalystsystem are described in U.S. Pat. Nos. 4,107,414; 4,186,107; 4,226,963;4,347,160; 4,382,019; 4,435,550; 4,465,782; 4,522,930; 4,530,912;4,532,313; 4,560,671; 4,657,882; 5,208,302; 5,902,765; 5,948,872;6,121,483; 6,436,864; 6,770,586; 7,022,640; 7,049,377; 7,202,314;7,208,435; 7,223,712; 7,351,778; 7,371,802; 7,491,781; 7,544,748;7,674,741; 7,674,943; 7,888,437; 7,888,438; 7,964,678; 8,003,558; and8,003,559, which are incorporated by reference herein.

Most of commercial propylene polymerization catalysts currently usedemploy alkyl phthalate esters as an internal electron donor. However,certain environmental issues have been recently raised concerning thecontinued use of phthalate derivatives in human contact applications. Asa result, the employment of a phthalate-free propylene polymerizationcatalyst is now necessary for the production of phthalate-freepolypropylene to remedy these issues.

U.S. Pat. No. 7,491,781 in particular teaches the use of an internaldonor in a propylene polymerization catalyst component which does notcontain a phthalate derivative. However the resulted propylenepolymerization catalyst has poorer hydrogen response and lowerisotacticity than the catalyst containing a phthalate derivative.

The polypropylene market also has an increasing demand in high melt flowrate (MFR) grade polypropylene to reduce cycle time and to achievedown-gauging while maintaining acceptable impact strength and stiffness.High MFR polypropylene is commonly achieved by adding peroxide to thepolymer, but such obtained polypropylene usually has odor issues and thephysical properties are sacrificed somehow. As such, production ofreactor-grade high MFR polypropylene becomes necessary to avoid theseissues.

There is a continuous need for developing catalyst systems that can beused to produce polyolefins, particularly polypropylene, which does notcontain a phthalate derivative. Furthermore, the desirable catalystsystems should also offer capabilities to produce polypropylene withacceptable isotacticity and high MFR.

SUMMARY OF THE INVENTION

This invention relates to heterocyclic organic compounds that may beemployed as an electron donor for polymerization catalyst systems, topolymerization catalyst systems employing the heterocyclic organiccompounds as an electron donor, to methods of making the polymerizationcatalyst systems, and to polymerization processes to producepolyolefins, particularly polypropylene, which does not contain aphthalate derivative.

In accordance with various aspects thereof, the present inventionrelates to a catalyst system for the polymerization or co-polymerizationof alpha-olefins comprising a solid Ziegler-Natta type catalystcomponent, a co-catalyst component, and optionally an external electrondonor component. The solid Ziegler-Natta type catalyst componentcomprises at least one heterocyclic organic compound of this invention.The heterocyclic organic compounds of the present invention that may beused as electron donors in polymerization catalyst systems arerepresented by Formula I:

wherein L is represented by Formula II:

or is selected from the groups consisting of —OR⁹, —SR⁹, —OCOR⁹,—COOR^(S), —NH₂, —NHR⁹, —NR⁹ ₂, and PR⁹ ₂, wherein R⁹ is a linear orbranch C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₃-C₂₀ cycloalkyl, C₆-C₂₀ aryl,C₇-C₂₀ alkylaryl or C₇-C₂₀ arylalkyl group, optionally containing atleast one heteroatom selected from the group consisting of B, Si andhalogen atoms. A and A₁, which may be identical or different, is acarbon atom or a heteroatom selected from the group consisting of Si, N,B, and P. Q and Q₁, which may be identical or different, is a heteroatomselected from the group consisting of O, N, S, and P.

R¹, R⁴, R⁵, and R⁸, which may be identical or different, are each ahydrocarbon-based substituent to Q, A, Q₁, and A₁, respectively. Thesubscripts p, q, i, and j, depending on the valence state of Q, A, Q₁,and A₁, are independently 0 or 1, which one of ordinary skill in the arthaving the benefit of this disclosure will recognize. The length andstructure of R¹, R⁴, R⁵, and R⁸ are not generally limited. In preferredembodiments of the present invention, R¹ and R⁵ are small groups such ashydrogen, methyl, or ethyl.

Wherein R, R², R³, R⁶, and R⁷, which may be identical or different, arebridging groups with a backbone chain length being 1-6 atoms for R and0-6 atoms for R², R³, R⁶, and R⁷, with the proviso that the resultantring structure is a three to eight-membered ring. “Backbone chainlength” in this context refers to the atoms that are in the directlinkage between the two atoms Q and A, Q₁ and A₁, or between the atom Aand the group L. For example, if —CH₂— or —CH₂—CH₂— is the bridginggroup, then the associated backbone chain length is one and two atoms,respectively, referring to the carbon atoms that provide the directlinkage between the two atoms. Similarly, if the bridging group has theiso-structure, CH₃CHCH₂, then the associated backbone chain length isalso two atoms.

The backbone of the bridging group is selected from the group consistingof aliphatic, alicyclic, and aromatic radicals. Preferably, the backboneof the bridging group is selected from the group consisting of aliphaticradicals, with or without unsaturation. The bridging group may have oneor more C₁-C₂₀ substituents (or side chains) extending off the backbonechain. The substituents may be branched or linear and may be saturatedor unsaturated. Similarly, the substituents may comprise aliphatic,alicyclic, and/or aromatic radicals.

One or more of carbon atom or hydrogen atom of R¹, R⁴, R⁵, R⁸, andbridging groups R, R², R³, R⁶, and R⁷, including any substituentsthereof, may be replaced with a heteroatom selected from the groupconsisting of O, N, S, P, B, Si, and halogen atoms, with the provisothat O, N, S, and P can only be embedded in the ring structure or in thebackbone atoms of R.

In various embodiments of the present invention, two or more of said R,R¹, R², R³, R⁴, R⁵, R⁶, R⁷, or R⁸ may be linked to form one or moresaturated or unsaturated monocyclic or polycyclic rings.

In various embodiments of the present invention, when the backbone of Rgroup is a single carbon atom, either A or A₁ cannot be connected to anitrogen atom to form a carbon nitrogen double bond.

In accordance with various aspects thereof, the present invention alsorelates to a composition containing a compound of the heterocyclicorganic compound of the aforementioned formula. In accordance withvarious aspects thereof, the present invention also relates to a methodof polymerizing an alpha-olefin comprising polymerizing the alpha-olefinin the presence of the heterocyclic organic compound of theaforementioned formula.

DESCRIPTION OF PREFERRED EMBODIMENTS

This invention relates to heterocyclic organic compounds that may beemployed as an electron donor for polymerization catalyst systems, topolymerization catalyst systems employing the heterocyclic organiccompounds as an electron donor, to methods of making such polymerizationcatalyst systems, and to polymerization processes to producepolyolefins, particularly polypropylene, which does not contain aphthalate derivative.

In accordance with various embodiments, a class of heterocyclic organiccompounds, which are useful as electron donors in polymerizationcatalyst systems for the production of polyolefins, particularlypolypropylene, are disclosed. These heterocyclic organic compounds maybe used as either an internal electron donor or an external electrondonor. Preferably, these heterocyclic organic compounds are used as aninternal electron donor. Polymerization catalyst systems employing theheterocyclic organic compounds of the present invention may have aninternal electron donor, an external electron donor, or both an internalelectron donor and an external electron donor.

The heterocyclic organic compounds of the present invention may be usedalone as a single constituent as the electron donor component of thecatalyst system or may be used in combination with one or more othercompounds as an electron donor component of the catalyst system. If morethan one compound is used as the electron donor component, one or moreof the constituents may be heterocyclic organic compounds of the presentinvention.

The heterocyclic organic compounds of the present invention that may beused as electron donors in polymerization catalyst systems arerepresented by Formula I:

wherein L is represented by Formula II:

or is selected from the groups consisting of —OR⁹, —SR⁹, —OCOR⁹, —COOR⁹,—NH₂, —NHR⁹, —NR⁹ ₂, and PR⁹ ₂, wherein R⁹ is a linear or branch C₁-C₂₀alkyl, C₂-C₂₀ alkenyl, C₃-C₂₀ cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀ alkylarylor C₇-C₂₀ arylalkyl group, optionally containing at least one heteroatomselected from the group consisting of B, Si and halogen atoms. A and A₁,which may be identical or different, is a carbon atom or a heteroatomselected from the group consisting of Si, N, B, and P. Q and Q₁, whichmay be identical or different, is a heteroatom selected from the groupconsisting of O, N, S and P.

R¹, R⁴, R⁵, and R⁸, which may be identical or different, are each ahydrocarbon-based substituent to Q, A, Q₁, and A₁, respectively. Thesubscripts p, q, i, and j, depending on the valence state of Q, A, Q₁,and A₁ are independently 0 or 1, which one of ordinary skill in the arthaving the benefit of this disclosure will recognize. The length andstructure of R¹, R⁴, R⁵, and R⁸ are not generally limited. In preferredembodiments of the present invention, R¹ and R⁵ are small groups such ashydrogen, methyl, or ethyl.

R, R², R³, R⁶, and R⁷, which may be identical or different, are bridginggroups with a backbone chain length being 1-6 atoms for R and 0-6 atomsfor R², R³, R⁶, and R⁷, with the proviso that the resulted ringstructure is a three to eight-membered ring. “Backbone chain length” inthis context refers to the atoms that are in the direct linkage betweenthe two atoms Q and A, Q₁ and A₁, or between the atom A and the group L.For example, if —CH₂— or —CH₂—CH2- is the bridging group then theassociated backbone chain length is one and two atoms, respectively,referring to the carbon atoms that provide the direct linkage betweenthe two atoms. Similarly, if the bridging group has the iso-structure,CH₃CHCH₂, then the associated backbone chain length is also two atoms.

The backbone of the bridging group is selected from the group consistingof aliphatic, alicyclic, and aromatic radicals. Preferably, the backboneof the bridging group is selected from the group consisting of aliphaticradicals, with or without unsaturation. The bridging group may have oneor more C₁-C₂₀ substituents (or side chains) extending off the backbonechain. The substituents may be branched or linear and may be saturatedor unsaturated. Similarly, the substituents may comprise aliphatic,alicyclic, and/or aromatic radicals.

One or more of carbon atom or hydrogen atom of R¹, R⁴, R⁵, R⁸, andbridging groups R, R², R³, R⁶, and R⁷, including any substituentsthereof, may be replaced with a heteroatom selected from the groupconsisting of O, N, S, P, B, Si, and halogen atoms with the proviso thatO, N, S, and P can only be embedded in the ring structure or in thebackbone atoms of R.

In various embodiments of the present invention, two or more of said R,R¹, R², R³, R⁴, R⁵, R⁶, R⁷, or R⁸ may be linked to form one or moresaturated or unsaturated monocyclic or polycyclic rings.

In various embodiments of the present invention, when the backbone of Rgroup is a single carbon atom, either A or A₁ cannot be connected to anitrogen atom to form a carbon nitrogen double bond.

Examples of suitable heterocyclic organic compounds of the Formula Iinclude, but not are limited to:

The heterocyclic organic compounds of the present invention may be usedas a component in Ziegler-Natta type catalyst systems. Except for theinclusion of the heterocyclic organic compounds of the presentinvention, the Ziegler-Natta type catalyst systems, and methods formaking such catalyst systems, which may be employed in accordance withthe various embodiments of the present invention, are not generallylimited. Typical, and acceptable, Ziegler-Natta type catalyst systemsthat may be used in accordance with the present invention comprise (a) asolid Ziegler-Natta type catalyst component, and (b) a co-catalystcomponent, and optionally (c) one or more external electron donors. Inaccordance with the various embodiments of the present invention, atleast one heterocyclic organic compound in accordance with the presentinvention is used as an electron donor in the Ziegler-Natta typecatalyst system. As previously disclosed herein, these heterocyclicorganic compounds may be used as either an internal electron donor or anexternal electron donor. Preferably, these heterocyclic organiccompounds are used as an internal electron donor.

Preferred solid Ziegler-Natta type catalyst component (a) include solidcatalyst components comprising a titanium compound having at least aTi-halogen bond and an internal electron donor compound supported on ananhydrous magnesium-dihalide support. Such preferred solid Ziegler-Nattatype catalyst component (a) include solid catalyst components comprisinga titanium tetrahalide. A preferred titanium tetrahalide is TiCl₄.Alkoxy halides may also be used.

If the heterocyclic organic compounds of the present invention are usedin combination with one or more other compounds as an internal electrondonor component of the catalyst system, the acceptable additionalinternal electron donor compounds for the preparation of solidZiegler-Natta type catalyst component (a) are not generally limited andinclude, but are not limited to, alkyl, aryl, and cycloalkyl esters ofaromatic acids, in particular the alkyl esters of benzoic acid andphthalic acid and their derivatives. Examples of such compounds includeethyl benzoate, n-butyl benzoate, methyl-p-toluate, andmethyl-p-methoxybenzoate and diisobutylphthalate. Other common internalelectron donors, including alkyl or alkyl-aryl ethers, ketones, mono- orpolyamines, aldehydes, and P-compounds, such as phosphines andphosphoramides, may also be used.

Acceptable anhydrous magnesium dihalides forming the support of thesolid Ziegler-Natta type catalyst component (a) are the magnesiumdihalides in active form that are well known in the art. Such magnesiumdihalides may be preactivated, may be activated in situ during thetitanation, may be formed in-situ from a magnesium compound, which iscapable of forming magnesium dihalide when treated with a suitablehalogen-containing transition metal compound, and then activated.Preferred magnesium dihalides are magnesium dichloride and magnesiumdibromide. The water content of the dihalides is generally less than 1%by weight.

The solid Ziegler-Natta type catalyst component (a) may be made byvarious methods. One such method consists of co-grinding the magnesiumdihalide and the internal electron donor compound until the productshows a surface area higher than 20 m²/g and thereafter reacting theground product with the Ti compound. Other methods of preparing solidZiegler-Natta type catalyst component (a) are disclosed in U.S. Pat.Nos. 4,220,554; 4,294,721; 4,315,835; 4,330,649; 4,439,540; 4,816,433;and 4,978,648. These methods are incorporated herein by reference.

In a typical solid Ziegler-Natta type catalyst component (a), the molarratio between the magnesium dihalide and the halogenated titaniumcompound is between 1 and 500 and the molar ratio between saidhalogenated titanium compound and the internal electron donor is between0.1 and 50.

Preferred co-catalyst component (b) include aluminum alkyl compounds.Acceptable aluminum alkyl compounds include aluminum trialkyls, such asaluminum triethyl, aluminum triisobutyl, and aluminum triisopropyl.Other acceptable aluminum alkyl compounds include aluminum-dialkylhydrides, such as aluminum-diethyl hydrides. Other acceptableco-catalyst component (b) include compounds containing two or morealuminum atoms linked to each other through hetero-atoms, such as:

-   -   (C₂H₅)₂Al—O—Al(C₂H₅)₂    -   (C₂H₅)₂Al—N(C₆H₅)—Al(C₂H₅)₂; and    -   (C₂H₅)₂Al—O—SO₂—O—Al(C₂H₅)₂.

Acceptable external electron donor component (c) is organic compoundscontaining O, Si, N, S, and/or P. Such compounds include organic acids,organic acid esters, organic acid anhydrides, ethers, ketones, alcohols,aldehydes, silanes, amides, amines, amine oxides, thiols, variousphosphorus acid esters and amides, etc. Preferred component (c) isorganosilicon compounds containing Si—O—C and/or Si—N—C bonds. Specialexamples of such organosilicon compounds are trimethylmethoxysilane,diphenyldimethoxysilane, cyclohexylmethyldimethoxysilane,diisopropyldimethoxysilane, dicyclopentyldimethoxysilane,isobutyltriethoxysilane, vinyltrimethoxysilane,dicyclohexyldimethoxysilane,3-tert-Butyl-2-isobutyl-2-methoxy-[1,3,2]oxazasilolidine,3-tert-Butyl-2-cyclopentyl-2-methoxy-[1,3,2]oxazasilolidine,2-Bicyclo[2.2.1]hept-5-en-2-yl-3-tert-butyl-2-methoxy-[1,3,2]oxazasilolidine,3-tert-Butyl-2,2-diethoxy-[1,3,2]oxazasilolidine,4,9-Di-tert-butyl-1,6-dioxa-4,9-diaza-5-sila-spiro[4.4]nonane,bis(perhydroisoquinolino)dimethoxy silane, etc. Mixtures of organicelectron donors may also be used. Finally, the heterocyclic organiccompounds of the present invention may also be employed as an externalelectronic donor.

The olefin polymerization processes that may be used in accordance withthe present invention are not generally limited. For example, thecatalyst components (a), (b) and (c), when employed, may be added to thepolymerization reactor simultaneously or sequentially. It is preferredto mix components (b) and (c) first and then contact the resultantmixture with component (a) prior to the polymerization.

The olefin monomer may be added prior to, with, or after the addition ofthe Ziegler-Natta type catalyst system to the polymerization reactor. Itis preferred to add the olefin monomer after the addition of theZiegler-Natta type catalyst system.

The molecular weight of the polymers may be controlled in a knownmanner, preferably by using hydrogen. With the catalysts producedaccording to the present invention, molecular weight may be suitablycontrolled with hydrogen when the polymerization is carried out atrelatively low temperatures, e.g., from about 30° C. to about 105° C.This control of molecular weight may be evidenced by a measurablepositive change of the Melt Flow Rate.

The polymerization reactions may be carried out in slurry, liquid or gasphase processes, or in a combination of liquid and gas phase processesusing separate reactors, all of which may be done either by batch orcontinuously. The polyolefin may be directly obtained from gas phaseprocess, or obtained by isolation and recovery of solvent from theslurry process, according to conventionally known methods.

There are no particular restrictions on the polymerization conditionsfor production of polyolefins by the method of this invention, such asthe polymerization temperature, polymerization time, polymerizationpressure, monomer concentration, etc. The polymerization temperature isgenerally from 40-90° C. and the polymerization pressure is generally 1atmosphere or higher.

The Ziegler-Natta type catalyst systems of the present invention may beprecontacted with small quantities of olefin monomer, well known in theart as prepolymerization, in a hydrocarbon solvent at a temperature of60° C. or lower for a time sufficient to produce a quantity of polymerfrom 0.5 to 3 times the weight of the catalyst. If such aprepolymerization is done in liquid or gaseous monomer, the quantity ofresultant polymer is generally up to 1000 times the catalyst weight.

The Ziegler-Natta type catalyst systems of the present invention areuseful in the polymerization of olefins, including but not limited tohomopolymerization and copolymerization of alpha olefins. Suitableα-olefins that may be used in a polymerization process in accordancewith the present invention include olefins of the general formulaCH₂═CHR, where R is H or C₁₋₁₀ straight or branched alkyl, such asethylene, propylene, butene-1, pentene-1,4-methylpentene-1 and octene-1.While the Ziegler-Natta type catalyst systems of the present inventionmay be employed in processes in which ethylene is polymerized, it ismore desirable to employ the Ziegler-Natta type catalyst systems of thepresent invention in processes in which polypropylene or higher olefinsare polymerized. Processes involving the homopolymerization orcopolymerization of propylene are preferred.

EXAMPLES

In order to provide a better understanding of the foregoing discussion,the following non-limiting examples are offered. Although the examplesmay be directed to specific embodiments, they are not to be viewed aslimiting the invention in any specific respect. The activity values (AC)in TABLE 1 are based upon grams of polymer produced per gram of solidcatalyst component used.

The following analytical methods are used to characterize the polymer.

Xylene soluble components (XS): 5.0 g of the polymer was added to 500 mlof xylenes (bp: 137˜140° C.) and dissolved while maintaining the mixtureat the boiling point over one hour. The mixture was cooled down to 5° C.within 20 minutes in an ice-water bath. Thereafter the ice-water bathwas replaced with a 20° C. water bath and the mixture was equilibratedat 20° C. for 30 minutes. The soluble matters were separated frominsoluble matters by filtration. The soluble components were dried withheating, and the polymer thus obtained was determined as xylene solublecomponents (wt %).

Melt Flow Rate: ASTM D-1238, determined at 230° C., under a load of 2.16kg.

Molecular Weight (Mn and Mw): The weight average molecular weight (Mw),number average molecular weight (Mn), and molecular weight distribution(Mw/Mn) of polymers are obtained by gel permeation chromatography onWaters GPCV 2000 system using Polymer Labs Plgel 10 um MIXED-B LS300×7.5 mm columns and 1,2,4-trichlorobenzene (TCB) as the mobile phase.The mobile phase is set at 1.0 ml/min, and temperature is set at 145° C.Polymer samples are heated at 150° C. for two hours. The injectionvolume is 299 microliters. External standard calibration of polystyrenenarrow standards is used to calculate the molecular weight.

Magnesium ethoxide (98%), anhydrous toluene (99.8%), TiCl₄ (99.9%),anhydrous n-heptane (99%), 2,2-dipyridylamine (99%), diisobutylphthalate (99%), cyclohexyl(dimethoxy)methylsilane (C-donor) (≧99%) andtriethylaluminum (93%) were all purchased from Sigma-Aldrich Co. ofMilwaukee, Wis., USA.

2,2′-Di(2-tetrahydrofuryl)propane [>96% (GC)], 2,2′-di(2-furyl)propane[>98.8% (GC)] and 2,2′-dipyrrolymethane [>97% (GC)] and ethylTetrahydrofuran-2-acetate [>98.0% (GC)] were purchased from TCI America.

Diisopropyldimethoxysilane (P-donor) was purchased from Gelest, Inc. ofMorrisville, Pa., USA.

Unless otherwise indicated, all reactions were conducted under an inertatmosphere.

Example 1 (A) the Preparation of a Solid Catalyst Component

A 250 ml flask equipped with a stirrer and thoroughly purged withnitrogen was charged with 10 g of magnesium ethoxide and 100 ml ofanhydrous toluene to form a suspension. To the suspension was injected25 ml of TiCl₄ and was then heated up to a temperature of 90° C. 1.8 gof 2,2-di(2-tetrahydrofuryl)propane was added thereto, followed byheating up to 110° C. with agitation at that temperature for 2 hours.After the completion of the reaction, the product was washed twice with100 ml of anhydrous toluene at 90° C., and 100 ml of fresh anhydroustoluene and 25 ml of TiCl₄ were added thereto for reacting withagitation at 110° C. for two additional hours. After the completion ofthe reaction, the product was washed 8 times with 200 ml of anhydrousn-heptane at 90° C. and was dried under a reduced pressure to obtain asolid composition.

(B) Polymerization

A bench scale 2-liter reactor was used. The reactor was first preheatedto at least 100° C. with a nitrogen purge to remove residual moistureand oxygen. The reactor was thereafter cooled to 50° C.

Under nitrogen, 1 liter dry heptane was introduced into the reactor.When reactor temperature was about 50° C., 4.3 ml triethylaluminum(0.58M, in hexanes), 0.40 ml cyclohexyl(dimethoxy)methylsilane (C-donor)(0.5 M in heptane), and then 30 mg of the solid catalyst componentprepared above were added to the reactor. The pressure of the reactorwas raised to 28.5 psig at 50° C. by introducing nitrogen. 8 psihydrogen in a 150 cc vessel was flushed into the reactor with propylene.

The reactor temperature was then raised to 70° C. The total reactorpressure was raised to and controlled at 90 psig by continuallyintroducing propylene into the reactor and the polymerization wasallowed to proceed for 1 hour. After polymerization, the reactor wasvented to reduce the pressure to 0 psig and the reactor temperature wascooled to 50° C.

The reactor was then opened. 500 ml methanol was added to the reactorand the resulting mixture was stirred for 5 minutes then filtered toobtain the polymer product. The obtained polymer was vacuum dried at 80°C. for 6 hours. The polymer was evaluated for melt flow rate (MFR),Xylene soluble (% XS), and molecular weight distribution (Mw/Mn). Theactivity of catalyst (AC) was also measured. The results are shown inTABLE 1.

Example 2

The preparation of a solid catalyst component was carried out under thesame conditions as Example 1 except that 0.85 g of2,2-di(2-furyl)propane was used in place of2,2-di(2-tetrahydrofuryl)propane.

Propylene polymerization was carried out in the same manner as describedin Example 1. The results are shown in TABLE 1.

Example 3

The preparation of a solid catalyst component was carried out under thesame conditions as Example 1 except that 1.03 g of2,2′-dipyrrolylmethane was used in place of2,2-di(2-tetrahydrofuryl)propane.

Propylene polymerization was carried out in the same manner as describedin Example 1 except that 8.6 ml triethylaluminum (0.58M), 0.80 mlcyclohexyl(dimethoxy)methylsilane (C-donor) (0.5 M in heptane), and then60 mg of the solid catalyst component were added to the reactor instead.The results are shown in TABLE 1.

Example 4

The preparation of a solid catalyst component was carried out under thesame conditions as Example 1 except that 1.7 g of 2,2′-dipyridylaminewas used in place of 2,2-di(2-tetrahydrofuryl)propane.

Propylene polymerization was carried out in the same manner as describedin Example 1. The results are shown in TABLE 1.

Example 5

The preparation of a solid catalyst component was carried out under thesame conditions as Example 1 except that magnesium ethoxide (6.0 g) and1.38 g of 2,2-di(2-thiophenyl)propane [>98.0% (GC), prepared accordingto the procedure described in Journal of the American Chemical Society1951, 73, 1377.] were used in place of 10 g magnesium ethoxide and 1.8 gof 2,2-di(2-tetrahydrofuryl)propane.

Propylene polymerization was carried out in the same manner as describedin Example 1. The results are shown in TABLE 1.

Example 6

The preparation of a solid catalyst component was carried out under thesame conditions as Example 1 except that 2.0 g of ethyltetrahydrofuran-2-acetate was used in place of2,2-di(2-tetrahydrofuryl)propane.

Propylene polymerization was carried out in the same manner as describedin Example 1 except that 0.4 ml diisopropyldimethoxysilane (P-donor)(0.5 M in Heptane) was used in place ofcyclohexyl(dimethoxy)methylsilane (C-donor). The results are shown inTABLE 1.

Comparative Example 1

The preparation of a solid catalyst component was carried out under thesame conditions as Example 1 except that 2.7 ml of diisobutyl phthalatewas used in place of 2,2-di(2-tetrahydrofuryl)propane.

Propylene polymerization was carried out in the same manner as describedin Example 1. The results are shown in TABLE 1.

Comparative Example 2

The solid catalyst component prepared in Comparative Example 1 was usedhere for the propylene polymerization which was carried out in the samemanner as described in Example 1 except that 0.4 mldiisopropyldimethoxysilane (P-donor) (0.5 M in Heptane) was used inplace of cyclohexyl(dimethoxy)methylsilane (C-donor). The results areshown in TABLE 1.

TABLE 1 External AC MFR XS Examples Internal donor donor (gPP/gCat)(g/10 min) (%) Mw/Mn Ex. 1 2,2-Di(2-tetrahydrofuryl)propane C-donor 255717 1.8 5.4 Ex. 2 2,2-Di(2-furyl)propane C-donor 1219 15 1.4 5.0 Ex. 32,2′-Dipyrrolylmethane C-donor 1065 5.5 2.4 6.2 Ex. 42,2′-Dipyridylamine C-donor 1893 18 1.7 4.7 Ex. 52,2-Di(2-thiophenyl)propane C-donor 2100 16 3.4 5.1 Com. Ex. 1Di-iso-butyl phthalate C-donor 2615 8 1.6 5.3 Ex. 6 EthylTetrahydrofuran-2-acetate P-donor 1487 15 3.3 4.9 Com. Ex. 2Di-iso-butyl phthalate P-donor 2896 4.2 1.1 5.5

As shown from the above results, the present inventive catalyst systemscan be used to produce polyolefins, particularly polypropylene, whichdoes not contain a phthalate derivative. Furthermore, the presentinventive catalyst systems also offer capabilities to producepolypropylene with acceptable isotacticity and high MFR.

Therefore, the present invention is well adapted to attain the ends andadvantages mentioned as well as those that are inherent therein. Theparticular embodiments disclosed above are illustrative only, as thepresent invention may be modified and practiced in different butequivalent manners apparent to those skilled in the art having thebenefit of the teachings herein. Furthermore, no limitations areintended to the details of construction or design herein shown, otherthan as described in the claims below. It is therefore evident that theparticular illustrative embodiments disclosed above may be altered ormodified and all such variations are considered within the scope andspirit of the present invention. Whenever a numerical range with a lowerlimit and an upper limit is disclosed, any number falling within therange is specifically disclosed. Moreover, the indefinite articles “a”or “an”, as used in the claims, are defined herein to mean one or morethan one of the element that it introduces.

1-29. (canceled)
 30. A solid catalyst component for the polymerizationor co-polymerization of alpha-olefins comprising titanium, magnesium,halogen and at least one internal electron donor selected fromheterocyclic organic compounds of:

wherein L is selected from the group consisting of —OR⁹, —SR⁹, —OCOR⁹,—COOR⁹, —NH₂, —NHR⁹, —NR⁹ ₂, and PR⁹ ₂; wherein R⁹ is selected from thegroup consisting of a linear or branch C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl,C₃-C₂₀ cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl, and C₇-C₂₀ arylalkyl;wherein A is a carbon atom or a heteroatom selected from the groupconsisting of Si, N, B, and P; wherein Q is a heteroatom selected fromthe group consisting of O, N, S, and P; wherein R¹ and R⁴, which may beidentical or different, are aliphatic, alicyclic or aromatic groups;wherein the subscripts p and q are independently selected from 0 or 1;wherein the bonds directly connected to Q and are independently a singlebond or a double bond; wherein R, R², and R³, which may be identical ordifferent, are bridging groups with a backbone chain length being 1-6atoms for R and 0-6 atoms for R² and R³, wherein the resultant ringstructure is a three to eight-membered ring.
 31. The solid catalystcomponent of claim 30, wherein R⁹ contains at least one heteroatomselected from the group consisting of B, Si, and halogen atoms.
 32. Thesolid catalyst component of claim 30, wherein the backbone of thebridging groups is selected from the group consisting of aliphatic,alicyclic, and aromatic radicals.
 33. The solid catalyst component ofclaim 30, wherein A cannot be connected to a nitrogen atom to form acarbon nitrogen double bond when the backbone of R group is a singlecarbon atom.
 34. The solid catalyst component of claim 30, wherein R¹ isselected from the group consisting of hydrogen, methyl, and ethyl. 35.The solid catalyst component of claim 30, wherein R, R², and R³independently comprise C₁-C₂₀ linear and/or branched substituents. 36.The solid catalyst component of claim 30, wherein two or more of said R,R¹, R², R³, and R⁴ may be linked to form one or more saturated orunsaturated monocyclic or polycyclic rings.
 37. The solid catalystcomponent of claim 30, wherein at least one of a carbon atom or hydrogenatom of R may be replaced by a heteroatom selected from the groupconsisting of O, N, S, P, B, Si, and halogen atoms, wherein O, N, S, andP can only be embedded in the backbone of the bridging groups.
 38. Thesolid catalyst component of claim 30, wherein at least one of a carbonatom or hydrogen atom of R¹, R², R³, and R⁴ may be replaced by aheteroatom selected from the group consisting of O, N, S, P, B, Si, andhalogen atoms, wherein O, N, S, and P can only be embedded in the ringstructure.
 39. A catalyst system for the polymerization orco-polymerization of alpha-olefins comprising: (1) a solid catalystcomponent for the polymerization or co-polymerization of alpha-olefincomprising titanium, magnesium, halogen and at least one internalelectron donor selected from heterocyclic organic compounds of:

wherein L is selected from the group consisting of —OR⁹, —SR⁹, —OCOR⁹,—COOR⁹, —NH₂, —NHR⁹, —NR⁹ ₂, and PR⁹ ₂: wherein R⁹ is selected from thegroup consisting of a linear or branch C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl,C₃-C₂₀ cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl, and C₇-C₂₀ arylalkyl;wherein A is a carbon atom or a heteroatom selected from the groupconsisting of Si, N, B, and P; wherein Q is a heteroatom selected fromthe group consisting of O, N, S, and P; wherein R¹ and R⁴, which may beidentical or different, are aliphatic, alicyclic or aromatic groups;wherein the subscripts p and q are independently selected from 0 or 1;wherein the bonds directly connected to Q and A, Q₁ are independently asingle bond or a double bond; wherein R, R², and R³, which may beidentical or different, are bridging groups with a backbone chain lengthbeing 1-6 atoms for R and 0-6 atoms for R² and R³, wherein the resultantring structure is a three to eight-membered ring; (2) a co-catalystcomponent.
 40. The catalyst system of claim 39, further comprising oneor more external electron donor components.
 41. The catalyst system ofclaim 39, wherein R⁹ contains at least one heteroatom selected from thegroup consisting of B, Si, and halogen atoms.
 42. The catalyst system ofclaim 39, wherein the backbone of the bridging groups is selected fromthe group consisting of aliphatic, alicyclic, and aromatic radicals. 43.The catalyst system of claim 39, wherein A cannot be connected to anitrogen atom to form a carbon nitrogen double bond when the backbone ofR group is a single carbon atom.
 44. The catalyst system of claim 39,wherein R¹ is selected from the group consisting of hydrogen, methyl,and ethyl.
 45. The catalyst system of claim 39, wherein R, R², and R³independently comprise C₁-C₂₀ linear and/or branched substituents. 46.The catalyst system of claim 39, wherein two or more of said R, R¹, R²,R³, and R⁴ may be linked to form one or more saturated or unsaturatedmonocyclic or polycyclic rings.
 47. The catalyst system of claim 39,wherein at least one of a carbon atom or hydrogen atom of R may bereplaced by a heteroatom selected from the group consisting of O, N, S,P, B, Si, and halogen atoms, wherein O, N, S, and P can only be embeddedin the backbone of the bridging groups.
 48. The catalyst system of claim39, wherein at least one of a carbon atom or hydrogen atom of R¹, R²,R³, and R⁴ may be replaced by a heteroatom selected from the groupconsisting of O, N, S, P, B, Si, and halogen atoms, wherein O, N, S, andP can only be embedded in the ring structure.
 49. A method forpolymerizing alpha-olefins, comprising polymerizing alpha-olefins in thepresence of: (1) a solid catalyst component for the polymerization orco-polymerization of alpha-olefin comprising titanium, magnesium,halogen and at least one internal electron donor selected fromheterocyclic organic compounds:

wherein L is selected from the group consisting of —OR⁹, —SR⁹, —OCOR⁹,—COOR⁹, —NH₂, —NHR⁹, —NR⁹ ₂, and PR⁹ ₂: wherein R⁹ is selected from thegroup consisting of a linear or branch C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl,C₃-C₂₀ cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl, and C₇-C₂₀ arylalkyl;wherein A is a carbon atom or a heteroatom selected from the groupconsisting of Si, N, B, and P; wherein Q is a heteroatom selected fromthe group consisting of O, N, S, and P; wherein R¹ and R⁴, which may beidentical or different, are aliphatic, alicyclic or aromatic groups;wherein the subscripts p and q are independently selected from 0 or 1;wherein the bonds directly connected to Q and A are independently asingle bond or a double bond; wherein R, R², and R³, which may beidentical or different, are bridging groups with a backbone chain lengthbeing 1-6 atoms for R and 0-6 atoms for R² and R³, wherein the resultantring structure is a three to eight-membered ring; (2) a co-catalystcomponent.
 50. The method of claim 49, further comprising one or moreexternal electron donor components.
 51. The method of claim 49, whereinR⁹ contains at least one heteroatom selected from the group consistingof B, Si, and halogen atoms.
 52. The method of claim 49, wherein thebackbone of the bridging groups is selected from the group consisting ofaliphatic, alicyclic, and aromatic radicals.
 53. The method of claim 49,wherein A cannot be connected to a nitrogen atom to form a carbonnitrogen double bond when the backbone of R group is a single carbonatom.
 54. The method of claim 49, wherein R¹ is selected from the groupconsisting of hydrogen, methyl, and ethyl.
 55. The method of claim 49,wherein R, R², and R³ independently comprise C₁-C₂₀ linear and/orbranched substituents.
 56. The method of claim 49, wherein two or moreof said R, R¹, R², R³, and R⁴ may be linked to form one or moresaturated or unsaturated monocyclic or polycyclic rings.
 57. The methodof claim 49, wherein at least one of a carbon atom or hydrogen atom of Rmay be replaced by a heteroatom selected from the group consisting of O,N, S, P, B, Si, and halogen atoms, wherein O, N, S, and P can only beembedded in the backbone of the bridging groups.
 58. The method of claim49, wherein at least one of a carbon atom or hydrogen atom of R¹, R²,R³, and R⁴ may be replaced by a heteroatom selected from the groupconsisting of O, N, S, P, B, Si, and halogen atoms, wherein O, N, S, andP can only be embedded in the ring structure.